The mushroom, Agaricus bisporus, is saprotrophic, i.e. it derives its nutrition from dead plant material by the extracellular enzymic digestion. It has a specific preference for partially-degraded cereal leaves (composted straw) rich in humic substances, and alive and dead microbes, rich in proteins. The mycelium of Agaricus bisporus synthesizes and excretes a range of enzymes which degrade the complex of soluble, insoluble and semi-crystalline polymers (including: cellulose, hemicellulose, lignin and its derivatives, proteins and humic-associated proteins).
These enzymes include:
- Carbohydrate Active Enzymes (CAZymes)
- Manganese peroxidases
- Heme thiolate peroxidases
- Copper radical oxidases
- Cytochrome P450s
- Serine proteinases
It is known that these enzymes are synthesized and released into the compost substrate to coincide and fuel the high nutrient demands when mushroom fruitbodies are produced. Investigations are underway to understand the control mechanisms involved in this coordinated regulation using genomics, molecular genetics and biochemical approaches.
In parallel, we are also conducting experiments and trials for the mushroom industry to examine the effects of mushroom supplements on mushroom crop yield, flushing pattern, and mushroom quality (measured as whiteness, texture, density and flavour). The responses to different classes of supplements is being examined on different compost types and using different strains of Agaricus bisporus.